Stabilization of antimicrobial coatings

ABSTRACT

Described herein is a coated building panel comprising: a substrate comprising a first major surface opposite a second major surface; a coating atop at least one of the first major surface or the second major surface, the coating comprising: a binder composition; an antimicrobial composition comprising a cationic compound; a stabilization composition comprising: a silicate compound; and a surfactant having an HLB value between about 10 and about 14.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application No. 63/188,582 filed on May 14, 2021. The disclosure of the above application is incorporated herein by reference.

BACKGROUND

The presence of bacteria, fungus, and/or viruses on surfaces is a major concern today affecting home, work, and recreational environments. Exposure to certain bacteria, fungi (or their spores), and/or viruses can seriously impact the health of humans, pets and other animals. Previous attempts at imparting protective properties to a building panel included applying an antibacterial and/or antifungal coating to a surface of a building material. However, such antimicrobial coatings may have been formulated at the expense of coating performance—such as uniformity, agglomeration, storage stability—thus, the need exists for a coating that can exhibit adequate protective performance without sacrificing necessary coating performance.

BRIEF SUMMARY

Described herein is a coated building panel comprising: a substrate comprising a first major surface opposite a second major surface; a coating atop at least one of the first major surface or the second major surface, the coating comprising: a binder composition; an antimicrobial composition comprising a cationic compound; a stabilization composition comprising: a silicate compound; and a surfactant having an HLB value between about 10 and about 14.

Other embodiments of the present invention include a coating composition comprising: a liquid carrier; a solid blend comprising: a binder composition; an antimicrobial composition comprising a cationic compound; a stabilization composition comprising: a silicate compound; and a surfactant having an HLB value between about 10 and about 14.

Other embodiments of the present invention include a method of forming a coated building panel comprising a) applying the coating composition according to the aforementioned coating composition to a substrate; and b) drying the coating composition so that substantially all liquid carrier is removed to form the coated building panel.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is top perspective view of a building panel according to the present invention;

FIG. 2 is a cross-sectional view of the building panel according to the present invention, the cross-sectional view being along the II line set forth in FIG. 1; and

FIG. 3 is a ceiling system comprising the building panel of the present invention.

DETAILED DESCRIPTION

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

As used throughout, ranges are used as shorthand for describing each and every value that is within the range. Any value within the range can be selected as the terminus of the range. In addition, all references cited herein are hereby incorporated by referenced in their entireties. In the event of a conflict in a definition in the present disclosure and that of a cited reference, the present disclosure controls.

Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material.

The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top,” and “bottom” as well as derivatives thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such.

Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the exemplified embodiments. Accordingly, the invention expressly should not be limited to such exemplary embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto.

Unless otherwise specified, all percentages and amounts expressed herein and elsewhere in the specification should be understood to refer to percentages by weight. The amounts given are based on the active weight of the material. According to the present application, the term “about” means +/−5% of the reference value. According to the present application, the term “substantially free” less than about 0.1 wt. % based on the total of the referenced value.

Referring to FIG. 1, the present invention includes a building panel 10 comprising a first major exposed surface 11 opposite a second major exposed surface 12 and a side exposed surface 13 that extends between the first major exposed surface 11 and the second major exposed surface 12, thereby defining a perimeter of the ceiling panel 10.

Referring to FIG. 3, the present invention may further include a ceiling system 1 comprising one or more of the building panels 10 installed in an interior space, whereby the interior space comprises a plenum space 3 and an active room environment 2. In such embodiments, the building panel 10 may be referenced as a ceiling panel 10. The plenum space 3 provides space for mechanical lines within a building (e.g., HVAC, plumbing, etc.). The active space 2 provides room for the building occupants during normal intended use of the building (e.g., in an office building, the active space would be occupied by offices containing computers, lamps, etc.).

In the installed state, the building panels 10 may be supported in the interior space by one or more parallel support struts 5. Each of the support struts 5 may comprise an inverted T-bar having a horizontal flange 31 and a vertical web 32. The ceiling system 1 may further comprise a plurality of first struts that are substantially parallel to each other and a plurality of second struts that are substantially perpendicular to the first struts (not pictured). In some embodiments, the plurality of second struts intersects the plurality of first struts to create an intersecting ceiling support grid. The plenum space 3 exists above the ceiling support grid 6 and the active room environment 2 exists below the ceiling support grid 6. In the installed state, the first major exposed surface 11 of the building panel 10 may face the active room environment 2 and the second major exposed surface 12 of the building panel 10 may face the plenum space 3.

Referring now to FIGS. 1 and 2, the building panel 10 of the present invention may have a panel thickness to as measured from the first major exposed surface 11 to the second major exposed surface 12. The panel thickness to may range from about 12 mm to about 40 mm—including all values and sub-ranges there-between. The building panel 10 may have a length L_(P) ranging from about 30 cm to about 310 cm—including all values and sub-ranges there-between. The building panel 100 may have a width WP ranging from about 10 cm to about 125 cm—including all values and sub-ranges there-between.

The building panel 10 may comprise a body 100 and a surface coating 200 applied thereto—as discussed further herein. The body 100 comprises an upper surface 111 opposite a lower surface 112 and a body side surface 113 that extends between the upper surface 111 and the lower surface 112, thereby defining a perimeter of the body 100. The body 100 may have a body thickness ti that as measured by the distance between the upper surface 111 to the lower surface 112 of the body 100. The body thickness ti may range from about 12 mm to about 40 mm—including all values and sub-ranges there-between.

The body 100 may be porous, thereby allowing airflow through the body 100 between the upper surface 111 and the lower surface 122—as discussed further herein. The body 100 may be comprised of a binder and fibers. In some embodiments, the body 100 may further comprise a filler and/or additive.

Non-limiting examples of binder may include a starch-based polymer, polyvinyl alcohol (PVOH), a latex, polysaccharide polymers, cellulosic polymers, protein solution polymers, an acrylic polymer, polymaleic anhydride, epoxy resins, or a combination of two or more thereof. Non-limiting examples of filler may include powders of calcium carbonate, limestone, titanium dioxide, sand, barium sulfate, clay, mica, dolomite, silica, talc, perlite, polymers, gypsum, wollastonite, expanded-perlite, calcite, aluminum trihydrate, pigments, zinc oxide, or zinc sulfate.

The fibers may be organic fibers, inorganic fibers, or a blend thereof. Non-limiting examples of inorganic fibers mineral wool (also referred to as slag wool), rock wool, stone wool, and glass fibers. Non-limiting examples of organic fiber include fiberglass, cellulosic fibers (e.g. paper fiber—such as newspaper, hemp fiber, jute fiber, flax fiber, wood fiber, or other natural fibers), polymer fibers (including polyester, polyethylene, aramid—i.e., aromatic polyamide, and/or polypropylene), protein fibers (e.g., sheep wool), and combinations thereof.

The porosity of the body 100 may allow for airflow through the body 100 under atmospheric conditions such that the building panel 10 may function as an acoustic building panel—specifically, an acoustic ceiling panel 10, which requires properties related to noise reduction and sound attenuation properties—as discussed further herein.

Specifically, the body 100 of the present invention may have a porosity ranging from about 60% to about 98%—including all values and sub-ranges there between. In a preferred embodiment, the body 100 has a porosity ranging from about 75% to 95%—including all values and sub-ranges there between. According to the present invention, porosity refers to the following:

% Porosity=[V _(Total)−(V _(Binder) +V _(F) +V _(Filler))]/V _(Total)

Where V_(Total) refers to the total volume of the body 100 defined by the upper surface 111, the lower surface 112, and the body side surfaces 113. V_(Binder) refers to the total volume occupied by the binder in the body 100. V_(F) refers to the total volume occupied by the fibers in the body 100. V_(Filler) refers to the total volume occupied by the filler in the body 100. V_(HC) refers to the total volume occupied by the hydrophobic component in the body 100. Thus, the % porosity represents the amount of free volume within the body 100.

The building panel 10 of the present invention comprising the body 100 may exhibit sufficient airflow for the building panel 10 to have the ability to reduce the amount of reflected sound in a room. The reduction in amount of reflected sound in a room is expressed by a Noise Reduction Coefficient (NRC) rating as described in American Society for Testing and Materials (ASTM) test method C423. This rating is the average of sound absorption coefficients at four ¼ octave bands (250, 500, 1000, and 2000 Hz), where, for example, a system having an NRC of 0.90 has about 90% of the absorbing ability of an ideal absorber. A higher NRC value indicates that the material provides better sound absorption and reduced sound reflection.

The building panel 10 of the present invention exhibits an NRC of at least about 0.5. In a preferred embodiment, the building panel 10 of the present invention may have an NRC ranging from about 0.60 to about 0.99—including all value and sub-ranges there-between.

The surface coating 200 of the present invention may be applied to at least one of the upper surface 111 and/or the body side surface 113 of the body 100. In some embodiments, the surface coating 200 of the present invention may be applied directly to at least one of the upper surface 111 and/or the body side surface 113 of the body 100. Although not pictured, in some embodiments, the building panel 10 may further comprise a scrim that is immediately adjacent to the upper surface 111 of the body 100. The scrim may comprise a first major surface opposite a second major surface, whereby the second major surface contacts the upper surface 111 of the body 100. In such embodiments, the surface coating 200 may be applied to the first major surface of the scrim.

he surface coating 200 may comprise an outer surface 201 opposite an inner surface 202. The inner surface 202 of the surface coating 200 faces toward the body 100 while the outer surface 201 of the surface coating 200 faces away from the body 100. The surface coating 200 may comprise a topcoat 210. The topcoat 210 may comprise an outer surface 211 opposite an inner surface 212. The topcoat 210 may have a topcoat thickness t₃ as measured between the inner surface 212 and the outer surface 211 of the topcoat 210.

The topcoat 210 may be applied to the upper surface 111 of the body 100 or the first major surface of the scrim. Once applied, the inner surface 212 of the topcoat 210 faces the upper surface 111 of the body 100 or the first major surface of the scrim, and the outer surface 211 of the topcoat 210 forms the first major exposed surface 11 of the building panel 10. Stated otherwise, the first major exposed surface 11 of the building panel 10 may comprises the outer surface 211 of the topcoat 210.

The surface coating 200 may comprise an edge-coat 230. The edge-coat 230 may comprise an outer surface 231 opposite an inner surface 232. The edge-coat 230 may be applied to the body side surface 113 of the body 100. Once applied, the inner surface 232 of the edge-coat 230 faces the body side surface 113 of the body 100 and the outer surface 231 of the edge-coat 230 forms the side exposed surface 13 of the building panel 10. Stated otherwise, the side exposed surface 13 of the building panel 10 may comprise the outer surface 231 of the edge-coat 230.

Although the building panel 10 shown in FIGS. 1 and 2 include both the topcoat 210 and the edge-coat 230, the present invention is not limited to surface coatings 200 that include both the topcoat 210 and the edge-coat 230. In some embodiments, the building panel 10 may comprise a surface coating 200 that includes only the topcoat 210—whereby the side exposed surface 13 of the building panel 10 is formed by the body side surface 113 of the body 100. In other embodiments, the building panel 10 may comprise a surface coating 200 that includes only the edge-coat 230—whereby first major exposed surface 11 of the building panel 10 is formed by either the upper surface 111 of the body 100, the first major surface of the scrim, or a coating applied thereto that is different from the surface coating 200 of the present invention.

The surface coating 200 is formed from a coating composition that may comprise a binder composition, an antimicrobial composition, and a stabilization composition. The surface coating may further comprise a pigment composition. The coating composition may further comprise one or more additives. The coating may be pigmented or non-pigmented—whereby non-pigmented coatings may be referred to as “clear coat” or “clear coating.”

The surface coating 200 is present in a dry-state. According to the present invention, the phrase “dry-state” refers to the coating composition being substantially free of a liquid carrier (e.g., liquid water). Thus, the surface coating 200, which is in the dry-state, may comprise the binder composition, antimicrobial composition, the stabilization composition, and additives while having less than about 0.1 wt. % of liquid carrier based on the total weight of the surface coating 200. In a preferred embodiment, the surface coating 200 in the dry-state has a solid's content of about 100 wt. % based on the total weight of the surface coating 200.

Conversely, the coating composition may be applied to either the body 100 or a scrim in a “wet-state,” which refers to the coating composition containing various amounts of liquid carrier—as discussed further herein. Therefore, in the wet-state, the coating composition may comprise at least the binder composition, the antimicrobial composition, the stabilization composition. In some embodiments, the coating composition in the wet-state may further comprise the additives. The liquid carrier may be selected from water, VOC solvent—such as acetone, toluene, methyl acetate—or combinations thereof. In a preferred embodiment, the liquid carrier is water and comprises less than 1 wt. % of VOC solvent based on the total weight of the liquid carrier.

In the wet-state, the coating composition may generally have a solids content ranging from about 5 wt. % to about 80 wt. %—including all percentages and sub-ranges there-between.

The solid's content is calculated as the fraction of materials present in the coating composition that is not the liquid carrier. Specifically, the solid's content of the coating composition in the wet-state may be calculated as the total amount of the coating composition in the dry-state the amount of the binder composition, the antimicrobial composition, and the stabilization composition) and dividing it by the total weight of the coating composition in the wet-state, including liquid carrier.

According to the embodiments where the coating composition forms a clear coating (i.e., no pigment), the coating composition in the wet-state may have a solids content ranging from about 19 wt. % to about 35 wt. % including all percentages and sub-ranges there-between, According to the embodiments where the coating composition forms a topcoat 210, the coating composition in the wet-state may have a solids content ranging from about 50 wt. % to about 75 wt. %—including all amounts and sub-ranges there-between. The topcoat 210 may comprise a pigment. According to the embodiments where the coating composition forms an edge-coat 230, the coating composition in the wet-state may have a solids content ranging from about 65 wt. % to about 85 wt. % including all amounts and sub-ranges there-between.

The coating composition may comprise the binder composition in an amount ranging from about 4.0 wt. % to about 85.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., as the surface coating 200—including all weight percentages and sub-ranges there-between.

According to the embodiments where the coating composition forms a clear coating (i.e., no pigment), the coating composition may comprise the binder composition in an amount ranging from about 65 wt. % to about 88 wt. % based on the total weight of coating composition in the dry-state—i.e., as the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms a pigmented coating topcoat 210, the coating composition may comprise the binder composition in an amount ranging from about 8 wt. % to about 18 wt. %—based on the total weight of coating composition in the dry-state—i.e., as the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms a pigmented edge-coat 230, the coating composition may comprise the binder composition in an amount ranging from about 10 wt. to about 20 wt. %—based on the total weight of coating composition in the dry-state—i.e., as the surface coating 200—including all weight percentages and sub-ranges there-between.

The binder composition may comprise a blend of one or more polymers. The polymers may be ionic. The polymers may be anionic. The polymers may exhibit a pH ranging from about 5.0 to about 9.0—including all pH values and sub-ranges there-between.

The polymeric binder may be one or more of a polyurethane, an acrylic polymer, an alkyd emulsion, and blends thereof.

Non-limiting examples of acrylic polymer, polymaleic anhydride, or a combination of two or more thereof. Non-limiting examples of polymeric binder may include a homopolymer or copolymer formed from the following monomers: vinyl acetate (i.e., polyvinyl acetate), vinyl propionate, vinyl butyrate, ethylene, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, ethyl acrylate, methyl acrylate, propyl acrylate, butyl acrylate, ethyl methacrylate, methyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, hydroxyethyl acrylate, styrene, butadiene, urethane, epoxy, melamine, and an ester. The polymeric binder may include one or more of aqueous lattices of polyvinyl acetate, polyvinyl acrylic, polyurethane, polyurethane acrylic, polystyrene acrylic, epoxy, polyethylene vinyl chloride, polyvinylidene chloride, and polyvinyl chloride.

In a non-liming embodiment, the binder may be a polymeric composition that is formed by curing an alkyd resin (also referred to as an alkyd emulsion). Non-limiting examples of alkyd emulsion include polyester resins which include residues of polybasic, usually di-basic, acid(s) and polyhydroxy, usually tri- or higher hydroxy alcohols and further including monobasic fatty acid residues. The monobasic residues may be derived (directly or indirectly) from oils (fatty acid triglycerides) and alkyd resins are also referred to as oil modified polyester resins.

The alkyd resins may be cured from residual carboxyl and hydroxyl functionality or by unsaturation (often multiple unsaturation) in the monobasic fatty acid residues. Alkyd resins may include other residues and/or additives to provide specific functionality for the intended end use e.g. sources of additional carboxyl groups may be included to improve water compatibility. One or more catalyst may be blended with an alkyd resin to help accelerate curing.

Alkyd resins may be prepared by reacting a monobasic fatty acid, fatty ester or naturally occurring, partially saponified oil with a glycol or polyol and/or a polycarboxylic acid.

Non-limiting examples of monobasic fatty acid, fatty ester or naturally occurring-partially saponified oil may be prepared by reacting a fatty acid or oil with a polyol. Examples of suitable oils include sunflower oil, canola oil, dehydrated castor oil, coconut oil, corn oil, cottonseed oil, fish oil, linseed oil, oiticica oil, soya oil, and tung oil, animal grease, castor oil, lard, palm kernel oil, peanut oil, perilla oil, safflower, tallow oil, walnut oil. Suitable examples of the fatty acid components of oil or fatty acids by themselves are selected from the following oil derived fatty acids; tallow acid, linoleic acid, linolenic acid, oleic acid, soya acid, myristic acid, linseed acid, crotonic acid, versatic acid, coconut acid, tall oil fatty acid, rosin acid, neodecanoic, neopentanoic, isostearic, 12-hydroxystearic, cottonseed acid with linoleic, linolenic and oleic being more preferred

Non-limiting examples of suitable glycol or polyol include aliphatic, alicyclic, and aryl alkyl glycols. Suitable examples of glycols include: ethylene glycol; propylene glycol; diethylene glycol; triethylene glycol; tetraethylene glycol; pentaethylene glycol; hexaethylene glycol; heptaethylene glycol; octaethylene glycol; nonaethylene glycol; decaethylene glycol; 1,3-propanediol; 2,4-dimethyl-2-ethyl-hexane-1,3-diol; 2,2-dimethyl-1,2-propanediol; 2-ethyl-2-butyl-1,3-propanediol; 2-ethyl-2-isobutyl-1,3-propanediol; 1,3-butanediol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; 2,2,4-tetramethyl-1,6-hexanediol; thiodiethanol; 1,2-cyclohexanedimethanol; 1,3-cyclohexanedimethanol; 1,4-cyclohexanedimethanol; 2,2,4-trimethyl-1,3-pentanediol; 2,2,4-tetramethyl-1,3-cyclobutanediol; p-xylenediol hydroxypivalyl hydroxypivalate; 1,10-decanediol; hydrogenated bisphenol A; trimethylolpropane; trimethylolethane; pentaerythritol; erythritol; threitol; dipentaerythritol; sorbitol; glycerine; trimellitic anhydride; pyromellitic dianhydride; dimethylolpropicnic acid and the like.

Non-limiting examples of polycarboxylic acid include isophthalic acid, terephthalic acid, phthalic anhydride (acid), adipic acid, tetrachlorophthalic anhydride, dodecanedioic acid, sebacic acid, azelaic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, maleic anhydride, fumaric acid, succinic anhydride (acid), 2,6-naphthalenedicarboxylic acid, glutaric acid and esters thereof.

The coating composition may comprise the antimicrobial composition in an amount ranging from about 0.1 wt. % to about 10.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms a clear coat, the coating composition may comprise the antimicrobial composition in an amount ranging from about 3.0 wt. % to about 10.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms a pigmented top coat 210, the coating composition may comprise the antimicrobial composition in an amount ranging from about 0.1 wt. % to about 0.5 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms an edge coat 230, the coating composition may comprise the antimicrobial composition in an amount ranging from about 0.3 wt. % to about 1.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between.

The antimicrobial composition may comprise one or more cationic compounds. The cationic compound may be a quaternary ammonium compound. The quaternary ammonium compound may have the following structure:

The groups R₁, R₂, R₃ and R₄ can vary within wide limits and examples of quaternary ammonium compounds that have anti-microbial properties will be well known to the person of ordinary skill in the art.

Each group R₁, R₂, R₃ and R₄ may, for example, independently be a substituted or unsubstituted and/or straight chain or branched and/or interrupted or uninterrupted alkyl, aryl, alkylaryl, arylalkyl, cyclo alkyl, (aromatic or non-aromatic) heterocyclyl or alkenyl group. Alternatively, two or more of R₁, R₂, R₃ and R₄ may together with the nitrogen atom form a substituted or unsubstituted heterocyclic ring. The total number of carbon atoms in the groups R₁, R₂, R₃ and R₄ must be at least 4. Typically the sum of the carbon atoms in the groups R₁, R₂, R₃ and R is 10 or more. In a preferred aspect of the invention at least one of the groups R₁, R₂, R₃ and R₄ contains from 8 to 18 carbon atoms. For example, 1, 2, 3 or 4 of R₁, R₂, R₃ and R₄ can contain from 8 to 18 carbon atoms or 10 to 16 carbon atoms.

Suitable substituents for the groups R₁, R₂, R₃ and R₄ may be selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, heterocyclyl, substituted heterocyclyl, cycloalkyl, substituted cycloalkyl, aryl, substituted aryl, alkylaryl, substituted alkylaryl, arylalkyl, substituted arylalkyl, F, Cl, Br, I, —OR′, —NR′R″, —CF₃, —CN, —NO₂, —C₂R′, —SR′, N₃, —C(═O)NR′R″, —NR′C(═O)R″, —C(═O)R′, —C(═O)OR′, —OC(═O)R′, —O(CR′R″)_(r)C(═O)R′, —O(CR′R″), —NR″C(═O)R′, —O(CR′R″)_(r)NR″SO₂R′, —OC(═O)NR′R″, —NR′C′(═O)OR″, —SO₂R′, —SO₂NR′R″, and —NR′SO₂R″, where R′ and R″ are individually, hydrogen, C₁-C₈ alkyl, cycloalkyl, heterocyclyl, aryl, or arylalkyl, and r is an integer from 1 to 6, or R′ and R″ together form a cyclic functionality, wherein the term “substituted” as applied to alkyl, alkenyl, heterocyclyl, cycloalkyl, aryl, alkylaryl and arylalkyl refers to the substituents described above, starting with F and ending with —NR′SO₂R″.

When one or more of R₁, R₂, R₃ and R₄ is interrupted, suitable interrupting groups include but are not limited to heteroatoms such as oxygen, nitrogen, sulphur, and phosphorus-containing moieties (e.g. phosphinate). A preferred interrupting group is oxygen.

Suitable anions for the quats include but are not limited to halide anions such as the chloride, fluoride, bromide or iodide and the non halide sulphonate.

In some embodiments, the quaternary ammonium compound may be those having the formula:

(CH₃)_(n)(A)_(m)N⁺X⁻

wherein A may be as defined above in relation to r₁, R², R₃ and R₄. X⁻ is selected from chloride, fluoride, bromide or iodide and sulphonate (preferably chloride or bromide), n is from 1 to 3 (preferably 2 or 3) and in is from 1 to 3 (preferably 1 or 2) provided that the sum of n and m is 4. Preferably, A is a C₆₋₂₀ (e.g. C₈₋₁₈, i.e. having 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms or C₈₋₁₂) substituted or unsubstituted and/or straight chain or branched and/or interrupted or uninterrupted alkyl, aryl, alkylaryl, arylalkyl or cycloalkyl group (wherein suitable substituents are as defined above in relation to R₁, R₂, R₃ and R₄). Each group A may be the same or different.

In some embodiments, the quaternary ammonium compound may be of the formula (CH₃)_(n)(A)_(m)N⁺X⁻ are those wherein n=3 and m=1. In such compounds A may be as defined above and is preferably, a C₆₋₂₀ substituted or unsubstituted and/or straight chain or branched and/or interrupted or uninterrupted alkyl, aryl, or alkylaryl group. Examples of this type of quaternary ammonium compound include Cetrimide (which is predominately trimethyltetradecylammonium bromide), dodecyltrimethylammonium bromide, trimethyltetradecylammonium bromide, hexadecytrimethylammonium bromide.

In other embodiments, the quaternary ammonium compound may be of the formula (CH₃)_(n)(A)_(m)N⁺X⁻ are those wherein n=2 and m=2. In such compounds A may be as defined above in relation to r₁, R₂, R₃ and R₄. Preferably A is a C₆₋₂₀ substituted or unsubstituted and/or straight chain or branched and/or interrupted or uninterrupted alkyl, aryl, or alkylaryl group. For example, A may represent a straight chain, unsubstituted and uninterrupted C₈₋₁₂ alkyl group or a benzyl group. In these compounds, the groups A may be the same or different. Examples of this type of compound include didecyl dimethyl ammonium chloride and dioctyl dimethyl ammonium chloride.

Non-limiting examples of quaternary ammonium compounds described above include the group of compounds which are generally called benzalkonium halides and aryl ring substituted derivatives thereof. Examples of compounds of this type include benzalkonium chloride, which has the structural formula:

wherein R may be as defined above in relation to R₁, R₂, R₃ and R₄. Preferably, R is a C₈₋₁₈ alkyl group or the benzalkonium chloride is provided and/or used as a mixture of C₈₋₁₈ alkyl groups, particularly a mixture of straight chain, unsubstituted and uninterrupted alkyl groups n-C₈H₁₇ to n-C₁₈H₃₇, mainly n-C₁₂H₂₅ (dodecyl), n-C₁₄H₁₉ (tetradecyl), and n-C₁₆H₃₃ (hexadecyl).

Other preferred quaternary ammonium compounds include those in which the benzene ring is substituted, for example alkyldimethyl ethylbenzyl ammonium chloride. As an example, a mixture containing, for example, equal molar amounts of alkyl dimethyl benzyl ammonium chloride and alkyldimethyl ethylbenzyl ammonium chloride nay be used.

Mixtures of, for example, one or more alkyl dimethyl benzyl ammonium chlorides and one or more compounds of formula (CH₃)₂(A)₂N⁺X⁻, such as didecyl dimethyl ammonium chloride may be used.

The coating composition may comprise the stabilization composition in an amount ranging from about 0.5 wt. % to about 15.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms the clear coat, the stabilization composition may be present in an amount ranging from about 8.0 wt. % to about 15.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms the pigmented top coat 210, the stabilization composition may be present in an amount ranging from about 0.5 wt. % to about 1.2 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms the edge coat 230, the stabilization composition may be present in an amount ranging from about 0.8 wt. % to about 2.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between.

The stabilization composition may comprise a surfactant. The coating composition may comprise the surfactant composition in an amount ranging from about 0.2 wt. % to about 14.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms the clear coat, the coating composition may comprise the surfactant composition in an amount ranging from about 6.0 wt. % to about 14.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition forms the pigmented top coat 210, the coating composition may comprise the surfactant composition in an amount ranging from about 0.2 wt. % to about 0.8 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between.

The term “surfactant” refers to synthetic and naturally occurring amphiphilic molecules that have hydrophobic portion(s) and hydrophilic portion(s). Due to the amphiphilic (amphipathic) nature, the surfactants and co-surfactants typically can reduce the surface tension between two immiscible liquids, for example, the oil and water phases in an emulsion, stabilizing the emulsion.

The amphiphilic (amphipathic) nature may result in a “hydrophilic-lipophilic balance” or otherwise referred to as a “hydrophile-lipophile balance” or “HLB”—which refers synonymously to a value that is used to index and describe a surfactant according to its relative hydrophobicity/hydrophilicity, relative to other surfactants. A surfactant's HLB value is an indication of the molecular balance of the hydrophobic and lipophilic portions of the surfactant, which is an amphipathic molecule. Each surfactant and mixture of surfactants (and/or co-surfactants) has an HLB value that is a numerical representation of the relative weight percent of hydrophobic and hydrophilic portions of the surfactant molecule(s). HLB values are derived from a semi-empirical formula. The relative weight percentages of the hydrophobic and hydrophilic groups are indicative of surfactant properties, including the molecular structure, for example, the types of aggregates the surfactant will form and the solubility of the surfactant.

HLB values may be a rough guide, hydrophilic surfactants are generally considered to be those compounds having an HLB value greater than about 10, as well as anionic, cationic, or zwitterionic compounds for which the HLB scale is not generally applicable. Similarly, hydrophobic surfactants are compounds having HLB value less than about 10. Stated otherwise, surfactants with HLB values greater than 10 or greater than about 10 are more soluble in aqueous compositions, for example, water, and are called “hydrophilic surfactants,” while surfactants having HLB values less than 10 or less than about 10 are more soluble in fats, oils and waxes, and are referred to as “hydrophobic surfactants” or “lipophilic surfactants.” Relatively amphiphilic surfactants are soluble in oil and water based liquids and typically have HLB values close to 1.0 or about 1.0.

Surfactant HLB values range from 1-45, while the range for non-ionic surfactants typically is from 1-20. The more lipophilic a surfactant is, the lower its HLB value. Conversely, the more hydrophilic a surfactant is, the higher its HLB value. The surfactant composition of the present invention may comprise one or more surfactants having an HLB value ranging from about 10 to about 14—including all HUB values and sub-ranges there-between. In some embodiments, the surfactant composition of the present invention may comprise one or more surfactants having an HLB value ranging from about 10 to about 12—including all HLB values and sub-ranges there-between.

Non-limiting examples of surfactants having an HLB value between about 10 and about 14 include polysorbate 81 (HLB 10); PEG-40 Sorbitan Hexaoleate (HLB 10); PEG-40 Sorbitan Perisostearate (HLB 10); PEG-10 Olive Glycerides (HLB 10); PEG sorbitol hexaoleate (HLB 10.2); Polysorbate 65 (HLB 10.51; PEG-25 Hydrogenated Castor Oil (HUB 10.8); Polysorbate 85 (HUB 11); PEG Glyceryl Cocoate (HLB 11); PEG-8 Stearate (HLB 11.1); PEG sorbitan tetraoleate (HLB 12); PEG-35 Almond Glycerides (HLB 12); PEG-10 oleyl ether (HLB 12.4); PEG-8 isooctylphenyl ether (HLB 12.4); PEG-10 stearyl ether (HLB 12.4); PEG-35 Castor Oil (HLB 12.5); PEG-10 cetyl ether (HLB 12.9); Nonoxyriol-9 (HLB 12.9); PEG-40 Castor Oil (HLB 13); PEG-10 isooctylphenyl ether (HLB 13.5); PEG-40 Hydrogenated Castor Oil (HLB 14)

The stabilization composition may comprise a silicate compound. The silicate compound may be thixotropic.

The coating composition may comprise the silicate compound in an amount ranging from about 0.1 wt. % to about 1.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments when the coating composition forms a clear coat, the silicate compound may be present in an amount ranging from about 0.6 wt. % to about 1.0 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments when the coating composition forms a pigment top coat 210, the silicate compound may be present in an amount ranging from about 0.1 wt. % to about 0.5 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between. According to the embodiments when the coating composition forms an edge coat, the silicate compound may be present in an amount ranging from about 0.1 wt. % to about 0.4 wt. %—based on the total weight of coating composition in the dry-state—i.e., the surface coating 200—including all weight percentages and sub-ranges there-between.

A weight ratio of the surfactant composition to the silicate compound may range from about 3.0:1.0 to about 1.0:1.0—including all ratios and sub-ranges there-between. In some embodiments, the weight ratio of the surfactant composition to the silicate compound may be about 3.0:1.0. In some embodiments, the weight ratio of the surfactant composition to the silicate compound may be about 2.5:1.0. In some embodiments, the weight ratio of the surfactant composition to the silicate compound may be about 2.0:1.0. In some embodiments, the weight ratio of the surfactant composition to the silicate compound may be about 3.0:2.0. In some embodiments, the weight ratio of the surfactant composition to the silicate compound may be about 1.0:1.0.

The silicate compound may be a lithium magnesium silicate. The silicate compound may be a synthetic clay. In one embodiment, the lithium magnesium silicate may have the formula:

[Mg_(w)Li_(x)Si₈O₂₀OH^(4−y)F_(y)]^(z−)

wherein w=3 to 6, x=0 to 3, y=0 to 4, z=12−2w−x, and the overall negative lattice charge is balanced by counter-ions; and wherein the counter-ions are selected from the group consisting of selected Na⁺, K⁺, NH₄ ⁺, Cs⁺, Li⁺, Mg⁺⁺, Ca⁺⁺, Ba⁺⁺, N(CH₃)₄ ⁺ and mixtures thereof. In some embodiments, the silicate compound may be lithium sodium magnesium silicate.

It has been discovered that the combination of the silicate compound and surfactant composition imparts a surprising stabilization effect to the coating when the coating comprises an binder composition comprising an anionic component and an antimicrobial composition comprising a cationic compound. The surprising stabilization effect results in the form of the coating composition not forming agglomeration/coagulation in the wet-state while also allowing for superior application characteristics (measured by drawdown).

The surface coating 200 may further comprise a pigment composition. The pigment composition may comprise one or more of titanium dioxide, alkaline metal carbonates, and combinations thereof.

The pigment composition may be present in an amount ranging from about 50 wt. % to about 90 wt. % based on the total weight of the pigment composition—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition may form a pigmented top coat 210, the pigment composition may be present in an amount ranging from about 65 wt. % to about 90 wt. % based on the total weight of the pigment composition—including all weight percentages and sub-ranges there-between. According to the embodiments where the coating composition may form a pigmented edge coat 230, the pigment composition may be present in an amount ranging from about 70 wt. % to about 90 wt. % based on the total weight of the pigment composition—including all weight percentages and sub-ranges there-between.

The surface coating 200 may comprise one or more additives. Additives may be present in the coating composition in an amount ranging from about 0.05 to about 2.5 wt. %—based on the total weight of the coating composition in the wet-state. Non-limiting examples of additives include, other biocides, defoamers, and the like.

Defoamers may include polyether siloxane. Defoamers may be present in an amount ranging from about 0.01 wt. % to about 0.05 wt. % based on the weight of the surface coating 200 in the dry-state.

The building panel 10 according to the present invention may be formed by applying the coating composition in the wet-state to either the body 100 or the scrim. Once applied, the coating composition in the wet-state may be dried at a temperature ranging from about 85° C. to about 135° C.—including all temperatures and sub-ranges there-between.

The coating composition may be applied by spray, roll, or vacuum coating.

After drying, all liquid carrier is driven off thereby leaving the surface coating 200—i.e., the coating composition in the dry-state. The surface coating 200 may be present in an amount ranging from about in an amount ranging from about 55 g/m² to about 1500 g/m²—including all amounts and sub-ranges there-between. According to the embodiments where the coating composition forms the face coating 210, the coating may be present in an amount ranging from 55 g/m² to about 360 g/m² including all amounts and sub-ranges there-between. According to the embodiments where the coating composition forms the edge coating 230, the coating may be present in an amount ranging from 750 g/m² to about 1500 g/m²—including all amounts and sub-ranges there-between.

EXAMPLES Experiment 1

A first series of experiments were performed to test the impact of combining the antimicrobial composition and stabilization composition of the present invention in a coating comprising a binder composition. Below is a list of components with relevant values and/or compositional information.

Liquid Carrier—including water

Binder—anionic emulsion polymer

Antimicrobial composition (“AC”)—quaternary ammonium compound

Silicate compound (“SC”)—lithium sodium magnesium silicate

Surfactant 1—HLB 8

Surfactant 2—HLB 10

Surfactant 3—HLB 12

Surfactant 4—HLB 14

TABLE 1 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 Ex. 7 Ex. 8 134E 134E 134E 134E 134E 134E 134E 134E Liquid Carrier 94.7 91.7 89.0 86.7 84.8 83.1 80.4 78.2 Binder 4.2 7.3 10.1 12.5 14.4 16.1 19.0 21.2 AC 0.2 0.2 0.2 0.2 0.2 0.2 0.1 0.1 SC 0.4 0.4 0.3 0.3 0.3 0.3 0.2 0.2 Surfactant 1 — — — — — — — — Surfactant 2 0.5 0.4 0.4 0.4 0.3 0.3 0.3 0.3 Surfactant 3 — — — — — — — — Surfactant 4 — — — — — — — — Agglomeration No No No No No No No No Draw Down Pass Pass Pass Pass Pass Pass Pass Pass Dry Time Pass Pass Pass Pass Pass Pass Pass Pass Ex. 9 Ex. 10 Ex. 11 Ex. 12 Ex. 13 Ex. 14 Ex. 15 134F 134F 134F 134F 134F 135C 135B Liquid Carrier 94.9 89.1 84.8 81.9 79.4 92.7 78.5 Binder 4.1 10.0 14.4 17.4 20.0 6.4 20.9 AC 0.2 0.2 0.2 0.2 0.1 0.2 0.1 SC 0.4 0.3 0.3 0.3 0.2 0.4 0.2 Surfactant 1 — — — — — 0.4 — Surfactant 2 — — — — — — — Surfactant 3 0.5 0.4 0.3 0.3 0.3 — — Surfactant 4 — — — — — — 0.2 Agglomeration No No No No No Yes No Draw Down Pass Pass Pass Pass Pass Fail Pass Dry Time Pass Pass Pass Pass Pass Pass Fail

Table 1 demonstrates that the coating formulation comprising the antimicrobial composition of a quaternary ammonium compound exhibits superior stability in the presence of a surfactant having an HLB between 10 and 14 as well as a silicate compound—whereby Example 14 demonstrates failing stability in the presence of a surfactant having an HLB less than 10 (i.e., an HLB value of 8).

An additional set of experiments were performed to test the impact of silicate compound with antimicrobial component.

TABLE 2 Ex. 16 Ex. 17 Ex. 18 Ex. 19 133A Page 132 Page 132 Page 132 Liquid Carrier 83.5 80.8 89.3 81.0 Binder 15.6 18.8 10.1 18.8 AC 0.3 0.2 0.3 0.2 SC 0.7 0.2 0.3 — Surfactant 1 — — — — Surfactant 2 — — — — Surfactant 3 — — — — Surfactant 4 — — — — Agglomeration Yes Yes Yes Yes Agglomeration Small Small Small Large Size Draw Down Fail Fail Fail Fail

As demonstrated by Table 2, the presence of the silicate compound alone is not enough to impart coating stability when the antimicrobial component is combined with an anionic polymer—further supporting the presence of the surfactant having an HLB value between 10 and 14 imparting an unexpected improvement in coating stability.

Experiment 2

A second experiment was performed to test the antimicrobial performance of the coating of the present invention. Two coating compositions were prepared—each comprising an anionic binder and liquid carrier. The first coating composition (Ex. 20) further comprising an antimicrobial composition comprising quaternary ammonium and a stabilization composition according to the present invention. The second coating composition (Ex. 21) further comprising an antimicrobial composition comprising a silver-based compound.

A first, second, and third Petri dish were inoculated with identical concentrations of Staphylococcus aureus ATCC 6538P and incubated for a period of 2 hours—whereby the initial bacteria concentration for each of the first, second, and third Petri dishes were recorded. After the initial incubation, a first amount of the first coating composition was applied to the first Petri dish (Ex. 20), a second amount of the second coating composition was applied to the second Petri dish (Ex. 21), and the third Petri dish was kept untreated (Control). After a second incubation period of 24-28 hours, a second bacteria concentration for each of the first, second, and third Petri dishes were records. The results are set forth below in Table 3.

TABLE 3 Ex. 20 Ex. 21 Control Coating Amount 2.0 g/ft² 2.5 g/ft² 0.0 g/ft² Second Bacterial −0.2 1.89 4.34 Concentration Bacterial Concentration 99.997 99.6 — Percent Reduction Value of Antimicrobial 2.45 4.54 — Activity (R)

As demonstrated by Table 3, the coating composition of the present invention (Ex. 20) surprisingly exhibits a superior antimicrobial activity as compared to a standard silver-based antimicrobial composition at even a lower application amount. The 0.397 percent improvement in bacterial concentration reduction (i.e., 99.997 vs. 99.6) is substantial as reflected by over 2.0 value improvement in Antimicrobial Activity Value (R). 

1. A coated building panel comprising: a substrate comprising a first major surface opposite a second major surface; a coating atop at least one of the first major surface or the second major surface, the coating comprising: a binder composition; an antimicrobial composition comprising a cationic compound; a stabilization composition comprising: a silicate compound; and a surfactant having an HLB value between about 10 and about
 14. 2. The coated building panel according to claim 1, wherein the binder composition comprises an anionic binder.
 3. The coated building panel according to claim 1, wherein the binder composition comprises an emulsion polymer, selected from an alkyd emulsion, styrene acrylic, and combinations thereof.
 4. (canceled)
 5. The coated building panel according to claim 1, wherein the binder composition is present in an amount ranging from about 4.0 wt. % to about 80.0 wt. % based on the total weight of the coating.
 6. The coated building panel according to claim 1, wherein the cationic compound comprises quaternary ammonium compounds, and wherein the quaternary ammonium compounds is present in an amount ranging from about 0.1 wt. % to about 10.0 wt. % based on the total weight of the coating.
 7. (canceled)
 8. The coated building panel according to claim 1, wherein the silicate compound is thixotropic, and wherein the silicate compound is present in an amount ranging from about 0.1 wt. % to about 1.0 wt. % based on the total weight of the coating.
 9. The coated building panel according to claim 1, wherein the silicate compound is lithium sodium magnesium silicate.
 10. (canceled)
 11. The coated building panel according to claim 1, wherein the surfactant is present in an amount ranging from about 0.2 wt. % to about 14.0 wt. % based on the total weight of the coating.
 12. The coated building panel according to claim 1, wherein the substrate is a fibrous body.
 13. A coating composition comprising: a liquid carrier; a solid blend comprising: a binder composition; an antimicrobial composition comprising a cationic compound; a stabilization composition comprising: a silicate compound; and a surfactant having an HLB value between about 10 and about
 14. 14. The coating composition according to claim 13, wherein the binder composition comprises an anionic binder.
 15. The coating composition according to claim 13, wherein the binder composition comprises an emulsion polymer, and wherein the emulsion polymer is selected from an alkyd emulsion, styrene acrylic, and combinations thereof.
 16. (canceled)
 17. The coating composition according to claim 13, wherein the binder composition is present in an amount ranging from about 4.0 wt. % to about 80.0 wt. % based on the total weight of the solid blend.
 18. The coating composition according to claim 13, wherein the cationic compound comprises quaternary ammonium compounds, and wherein the quaternary ammonium compounds is present in an amount ranging from about 0.1 wt. % to about 10.0 wt. % based on the total weight of the solid blend.
 19. (canceled)
 20. The coating composition according to claim 13, wherein the silicate compound is thixotropic, and wherein the silicate compound is present in an amount ranging from about 0.1 wt. % to about 1.0 wt. % based on the total weight of the solid blend.
 21. The coating composition according to claim 13, wherein the silicate compound is lithium sodium magnesium silicate.
 22. (canceled)
 23. The coating composition according to claim 13, wherein the surfactant is present in an amount ranging from about 0.2 wt. % to about 14.0 wt. % based on the total weight of the solid blend.
 24. The coating composition according to any one of claims 13 to 23, wherein the liquid carrier comprises water, and wherein the liquid carrier is present in an amount ranging from about 5.0 wt. % to about 80.0 wt. % based on the total weight of the coating composition.
 25. (canceled)
 26. A method of forming a coated building panel comprising a) applying the coating composition according to claim 13 to a substrate; and b) drying the coating composition so that substantially all liquid carrier is removed to form the coated building panel, wherein step b) is performed at a temperature ranging from about 80° C. to about 135° C.
 27. The method according to claim 26 wherein the substrate comprises a fibrous body.
 28. (canceled) 